Probability of Getting a Job

Date: 7/10/96 at 18:52:11
From: Anonymous
Subject: Probability with Different Events
If a person is applying for five different jobs and has a ten percent
chance of getting any one job, what is the probability of getting any
job at all?
I eliminated adding the probabilities, so I know my odds aren't
50 percent. Then I thought maybe the odds are only as good as your
probability of getting the highest likelihood for a job, in this case
10 percent. But it seems as if there must be some benefit in applying
for more jobs. Do you multiply the odds, i.e.
.9*.9*.9*.9*.9 = 45 percent chance of not getting any job?.

Date: 7/10/96 at 20:6:33
From: Doctor Anthony
Subject: Re: Probability with Different Events
Note that in the situation you describe you could end up with
0, 1, 2,...5 jobs, so giving 6 possible outcomes. If you wanted the
probability of say 3 jobs you would use the binomial probability
expression
P(3) = 5C3*0.10^3*0.9^2 = .0081
{where 5C3 = 5*4*3/(1*2*3) = 10}
However, the easiest way to tackle this type of probability is to
consider that the probability of at least one job is 1 - prob.(no job)
= 1 - 0.9^5
= 1 - 0.59
= 0.4095
-Doctor Anthony, The Math Forum
Check out our web site! http://mathforum.org/dr.math/